Water-swellable, bead copolymer

Abstract

Water-swellable, cross-linked, bead copolymers of (A) an ethylenically unsaturated monomer having a carboxylic acid anhydride, glycidyl or succinimide group, (B) a comonomer having at least two radical-polymerizable carbon double bonds, and (C) a radical-polymerizable water-soluble comonomer are disclosed to be excellent carriers capable of bonding with biologically active substances such as enzymes, enzyme substrates, inhibitors, hormones, antibiotics, antigens, and peptides.

What is claimed is: 
     
       1. A water-swellable, cross-linked bead copolymer prepared by the method comprising: a. dissolving a monomer mixture consisting essentially of   
     
     
       1. an ethylenically-unsaturated radical-polymerizable comonomer having a glycidyl group, 2. a cross-linking comonomer having at least two radical-polymerizable α, β-carbon double bonds, but otherwise free of the functional groups found in monomer (1),   3. a radical-polymerizable water-soluble mono-unsaturated comonomer,   comonomers (1), (2), and (3) constituting from about 50 to 100 mol percent of the monomer mixture with the balance, if any, being 4. a water-insoluble radical-polymerizable mono-unsaturated compound,     comonomer (1) comprising at least 2 mol percent, comonomer (2) comprising 0.2 to 5 mol percent, and comonomer (3) comprising at least 10 mol percent of the monomer mixture, in from 20 to 200 percent, by weight of the monomer mixture, of a non-aqueous solvent for said monomer mixture;   b. combining the solution with a free radical-forming initiator soluble in said solution;   c. suspending the resulting solution, in the form of droplets, in a continuous phase of a non-polar organic liquid which is immiscible with said non-aqueous solvent and is not a solvent for said monomer or said initiator;   d. polymerizing said monomer mixture at a temperature at which said initiator forms free radicals, whereby said bead copolymer is formed; and   e. separating said bead copolymer from said continuous phase of organic liquid.   
     
     
       2. A copolymer as claimed in claim 1 which is washed with an anhydrous solvent after separation from said continuous phase of organic liquid. 
     
     
       3. A copolymer as claimed in claim 2 which is washed with acetone after separation from said continuous phase of organic liquid. 
     
     
       4. A copolymer as in claim 1 wherein comonomer (1) is an ester or ether formed between a glycidyl alcohol and an unsaturated carboxylic acid or an unsaturated alcohol, respectively. 
     
     
       5. A copolymer as in claim 1 wherein comonomer (1) is allyl glycidyl ether or an acrylate or methacrylate ester of an aliphatic or cycloaliphatic glycidyl alcohol or glycidyl ether alcohol having 3 to 18 carbon atoms. 
     
     
       6. A copolymer as in claim 1, wherein comonomer (2) is a mono- or lower polyethylene glycol dimethacrylate or diacrylate, divinyl benzene, triallyl cyanurate, methylene-bisacrylamide or methacrylamide, or a combination thereof. 
     
     
       7. A copolymer as in claim 6, wherein comonomer (2) is ethylene- or triethylene glycol dimethacrylate. 
     
     
       8. A copolymer as in claim 1, wherein comonomer (3) is a vinyl or vinylidene compound containing an amido, hydroxyl, carboxyl, tertiary amino, quaternary ammonium or sulfonic acid group. 
     
     
       9. A copolymer as in claim 8, wherein comonomer (3) is a vinyl or vinylidene compound containing an amido group. 
     
     
       10. A copolymer as in claim 1, wherein comonomer (3) is acryl- or methacrylamide, vinyl pyrrolidone, ethylene glycol- or propylene glycol monoacrylate or monomethacrylate, acrylic- or methacrylic acid, dialkylaminoethyl acrylate or methacrylate with 1 to 4 carbon atoms in the alkyl substituents, vinyl sulfonic acid, sulfoethyl acrylate or methacrylate, a salt thereof, or a combination thereof. 
     
     
       11. A copolymer as in claim 1, wherein the content of comonomer (3) is more than 20% by weight. 
     
     
       12. A copolymer as in claim 11, wherein the content of comonomer (3) is from 50 to 80% by weight.